usb 4-1: New USB device found, idVendor=0e8d, idProduct=763f, bcdDevice=9b.23 usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 4-1: Product: syz usb 4-1: Manufacturer: syz usb 4-1: SerialNumber: syz usb 4-1: USB disconnect, device number 2 ================================================================== BUG: KASAN: slab-use-after-free in btusb_disconnect+0x4dc/0x580 drivers/bluetooth/btusb.c:4356 Read of size 4 at addr ffff8881000a47c0 by task kworker/1:1/37 CPU: 1 UID: 0 PID: 37 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 btusb_disconnect+0x4dc/0x580 drivers/bluetooth/btusb.c:4356 usb_unbind_interface+0x1da/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] device_remove+0x122/0x170 drivers/base/dd.c:563 __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1297 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579 device_del+0x396/0x9f0 drivers/base/core.c:3878 usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x9c0 drivers/usb/core/hub.c:2344 hub_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1aa2/0x5060 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 37: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kmalloc_node_track_caller_noprof+0x212/0x4c0 mm/slub.c:4395 alloc_dr drivers/base/devres.c:119 [inline] devm_kmalloc+0xa5/0x260 drivers/base/devres.c:864 devm_kzalloc include/linux/device/devres.h:53 [inline] btusb_probe+0x23f/0x4480 drivers/bluetooth/btusb.c:3961 usb_probe_interface+0x303/0xa40 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xa90 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1aa0 drivers/base/core.c:3689 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xa90 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1aa0 drivers/base/core.c:3689 usb_new_device+0xd07/0x1a60 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2fce/0x5060 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 37: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x3e/0x50 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x283/0x470 mm/slub.c:4894 release_nodes+0x11e/0x240 drivers/base/devres.c:506 devres_release_all+0x112/0x180 drivers/base/devres.c:535 device_unbind_cleanup+0x19/0x1f0 drivers/base/dd.c:550 __device_release_driver drivers/base/dd.c:1279 [inline] device_release_driver_internal+0x4c3/0x620 drivers/base/dd.c:1297 usb_driver_release_interface+0x109/0x190 drivers/usb/core/driver.c:640 btusb_disconnect+0x448/0x580 drivers/bluetooth/btusb.c:4349 usb_unbind_interface+0x1da/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] device_remove+0x122/0x170 drivers/base/dd.c:563 __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1297 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579 device_del+0x396/0x9f0 drivers/base/core.c:3878 usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x9c0 drivers/usb/core/hub.c:2344 hub_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1aa2/0x5060 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8881000a4000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1984 bytes inside of freed 2048-byte region [ffff8881000a4000, ffff8881000a4800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1000a0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042000 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888100042000 0000000000000000 dead000000000001 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0200000000000003 ffffea0004002801 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 0, tgid 0 (swapper/0), ts 1657545179, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0xf98/0x2ce0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x259/0x21e0 mm/page_alloc.c:5148 alloc_pages_mpol+0xe4/0x410 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xc55/0x1620 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __kmalloc_cache_node_noprof+0x208/0x3c0 mm/slub.c:4415 kmalloc_node_noprof include/linux/slab.h:928 [inline] get_unbound_pool kernel/workqueue.c:5035 [inline] alloc_unbound_pwq+0x5fc/0xe10 kernel/workqueue.c:5163 apply_wqattrs_prepare+0x3af/0xbd0 kernel/workqueue.c:5288 apply_workqueue_attrs_locked+0x64/0xe0 kernel/workqueue.c:5364 alloc_and_link_pwqs kernel/workqueue.c:5521 [inline] __alloc_workqueue+0x1007/0x1810 kernel/workqueue.c:5736 alloc_workqueue_noprof+0xd2/0x200 kernel/workqueue.c:5786 workqueue_init_early+0xd46/0x1480 kernel/workqueue.c:7809 start_kernel+0x1da/0x4d0 init/main.c:989 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 page_owner free stack trace missing Memory state around the buggy address: ffff8881000a4680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881000a4700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881000a4780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881000a4800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881000a4880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================